Condensate pans and plumbing in the air handling units of air conditioners are exposed to the atmosphere which contains many microorganisms. Some of these enter the water and multiply. The build up may mechanically obstruct outflow passages, causing overflow of condensate, for example. In an unattended apartment, in a multistory building, this causes considerable property damage and liability disputes. In certain situations, pathogenic microorganisms may grow in a cooling tower, resulting in a Legionaire's disease epidemic, for example.
Prior art solutions have included periodic cleaning and manual introduction of biocidal material into the condensate pan in liquid form, as solids such as large tablets or briquettes which slowly dissolve, and pads which slowly diffuse their biocidal contents into the water. These approaches are labor intensive, apply treatment in an inconsistent and nonuniform manner to either provide inadequate concentrations or wasteful amounts or both such as a high concentration that diminishes as the material is progressively eluted or dissolved.